Since launching in 2005, calorie-counting and exercise-tracking app MyFitnessPal has boostrapped its way to a profitable business reaching more than 40 million users worldwide. But, after years of going it alone, the company said on Sunday that it had raised $18 million from some of Silicon Valley’s biggest investors.

The Series A round was led by Kleiner Perkins Caufield & Byers and included Accel Partners. As part of the deal, Kleiner Perkins’ John Doerr and Accel’s Andrew Braccia will join the company’s board.

With the new funding, co-founder Mike Lee said MyFitnessPal plans to invest in product development and growing its team of about 40 people. It also plans to push further into international markets — earlier this summer, it launched new versions in Spanish, French, German and Portugese to help drive business in Europe and South America.

Given rising interest in digital health and fitness tools, it’s not surprising to see the company redouble its efforts with investors. Between 2012 and 2017, worldwide downloads of sports and fitness mobile apps are expected to grow 63 percent, according to a recent report from research firm IHS Electronics and Media. As interest in health-tracking devices also continues to climb, MyFitnessPal, which integrates with gadgets like the Fitbit (see disclosure) and Jawbone Up (as well as some other fitness apps), sees an opportunity in being a central health- and fitness-related data hub.

“MyFitnessPal will help you glean and discover insights from that data,” Lee said. “By combining population data with personal data, we’ll be able to provide personal analysis to help individuals achieve their goals.”

The app already collects millions of data points on users’ diets and exercise regimes, including what they eat, whether they eat at home or restaurants, how often they exercise and the amount of weight that they lose. With the explosion of wearable sensors, Lee added, data collection on health- and fitness-related decisions and outcomes will only grow. MyFitnessPal is currently ad-supported but, as it offers more data-driven products, it will be interesting to see what kinds of revenue streams it might add.

Disclosure: Fitbit is backed by True Ventures, a venture capital firm that is an investor in the parent company of GigaOM. Om Malik, founder of GigaOM, is also a venture partner at True.